The invention relates to vacuum treatment of an input stream for separation into diverse streams of distinct fractions. More particularly, the invention accomplishes such treatment and separation by various means including without limitation vacuum and heating processes, mechanical processes, as well as without limitation flash-steam production and pneumatic-conveyance drying.
A preferred input material includes without limitation empty broken egg shells, as a by-product of the like from egg-producing or -utilizing operation. It is preferred to separate empty broken egg shells into two fractions, namely a mineral powder in contrast to petals of membrane. Membrane desirably contains, among other constituents, collagen, the protein of connective tissue. The membrane fraction is optimally rendered by the treatment in accordance with the invention to be pathogen free:—that is, not merely allergen free or allergy tested but, even better, pathogen free.
As for terminology, it is preferred to construe “egg shells” as consisting of soft “membrane” and hard “mineral.” In other words, it is preferred to avoid confusion between the terms “shell” and the “mineral” by using the term “mineral” as the counterpart of “membrane” in the twosome of “mineral” and “membrane.”
Abundant supplies of fresh and uncontaminated, broken empty egg shells are readily available from various sources including without limitation large-scale foodstuff industries which are predominantly interested only in the albumen (white) and yolk. In such large-scale operations, the empty broken eggshells are an un-used or under-utilized by-product thereof. It is an object of the invention to improve utilization of such.
It is another object of the invention to input a continuous stream of broken empty egg shells and separate such into a soft membrane fraction as well as, in contrast, a hard mineral fraction. In terms of the soft membrane fraction, it is more accurate to say that an avian egg has both an inner and outer membrane layer, which among other things are divided where they line the air cell in the bulbous end of an egg. However, for purposes of this description, the membrane fraction of empty broken egg shells will be predominantly treated as one thing, and without more technically accurately distinguishing between inner and outer layers thereof.
It is preferred in accordance with the invention to recover the hard mineral fraction in a dry stream of bits or dust, or as another way of reckoning things, a powder. In contrast, it is preferred in accordance with the invention to recover the soft membrane fraction in a stream of flakes or shreds which for convenience of this written description and without limiting the invention are hereafter referred to as “petals.” The term “petal” is no term of art but instead is adopted in view of that at least one preferred texture for the output stream of the membrane fraction can be reckoned to something in ordinary experience as most likely approximating fresh rose petals.
One aspect of the invention is to gain control over textural and structural changes to the membrane fraction as it undergoes the method in accordance with the invention. Underneath a scanning microscope, fresh membranes can be resolved into a feltwork of interlacing fibers of variable diameter. S. E. Solomon, Egg and Eggshell Quality, p. twenty-two (Iowa State Univ. Press 1997). The membrane fibers comprise a fairly simple arrangement of protein and carbohydrate (in contrast to albumen which is an admixture of some forty structurally distinct proteins), wherein chemical variation therein is fairly confined to the end portions of the fibers of the outer membrane. Id, p. ninety-three.
It is estimated that about 10% of egg shell membrane weight comprises collagen, the main protein of connective tissue. In general overview of the foregoing, egg shell membrane comprises an organic biochemistry that nowadays is more greatly appreciated for being a source of some highly valuable constituents. It is an object of the invention to separate a membrane fraction from empty broken egg shells without changing (much, if at all) the delicate constituents (eg., molecules and the like), to the extent practicable.
The inventive method and apparatus utilizes in part various heat processes to accomplish drying and/or separation as described more particularly below. However, there are worrisome aspects over what heat will do to the delicate molecules and the like in the membrane, including the protein and connective tissue constituents (it is noted that, while carbohydrates also change with heat they usually can withstand higher temperatures than proteins, and oils can usually withstand higher temperatures still). Simply put, elevated temperatures produce physical changes in proteins and connective tissue. The applicable phenomena are better understood by food scientists, as in more particular connection with foodstuffs, such as cuts of beef. Without knowing for sure, certainly some of the understanding for beef is fairly transferable to egg shell membranes. Hence the following for now is at least more accurate in connection with beef.
Food scientists know that beef-steaks undergo physical changes with temperatures ranging from 54° C. (130° F.) (eg., very rare) to 82° C. (180° F.) (eg., very well done), which corresponds to changes in color from deep red or purple to pale gray. The color changes are a result of the “denaturation” of myoglobin in the beef. Denaturation is the physical unfolding of proteins in response to such influences as extreme heat. The denaturation of myoglobin (eg., a red iron-containing protein pigment in muscles that is similar to hemoglobin) make the protein unable to bind oxygen, causing color change from bright cherry red of oxymyoglobin to the brown of denatured myoglobin (equivalent to metmyoglobin). Ie., The New Encyclopaedia Britannica, Volume 19 of the Macropaedia, the entry under “Food Processing,” p. three-hundred eighty-one (® 2002).
In regards of structural changes, the color changes seen during the cooking of beef correspond to structural changes also taking place. The structural changes are due to the effects of heat on collagen (again, connective tissue proteins) and actin and myosin (myofibrillar proteins). In the temperature range between 50° C. and 71° C. (122° F. and 160° F.) connective tissue in meat begins to shrink. Further heating to temperatures above 71° C. causes the complete denaturation of collagen into a gelatin-like consistency. As an aside, that circumstance leads to cooks cooking tough meats, which have relatively high amounts of connective tissues, slowly under moist conditions to internal temperatures above 71° C., so that a tough meat is tenderized by the fact of gelatinization of the collagen while at the same time the moist conditions maintain juiciness.
The myofibrillar proteins also experience major changes during cooking. In the range of 40° C. to 50° C. (104° F. to 122° F.) actin and myosin begin to lose solubility as heat denaturation begins. At temperatures of 66° C. to 77° C. (150° F. to 170° F.) the myofibrillar proteins begin to shorten and toughen. Beyond 77° C. (170° F.) proteins begin to lose structural integrity (ie., they are completely denatured) and, at least for the sake of culinary arts, tenderness begins to improve. And so in general, meats with low amounts of connective tissue are most tender when served closer to medium rare or rare so that muscle proteins are not hardened. Conversely, meats with heavy amounts of connective tissue require slow cooking closer to well done in order to achieve collagen gelatinization.
It is not known how much of the foregoing is applicable to the issues surrounding heat and egg shell membrane. Nevertheless, moderate heat will certainly cause egg shell membrane to shrink and toughen, although extreme heat will not as much as gelatinize membrane but instead turn it to ash. It is an object of the invention to minimize or manage change to the membrane fraction, if not eliminate such change altogether. Users of the inventive method and apparatus will at times desire a membrane output whose texture most closely resembles fresh rose petals. Perhaps this texture might correspond to something like what?, “very rare” or “rare?” At other times, an acceptable texture might be slightly shrunken and tougher. Perhaps that texture might correspond to what?, medium? It is generally not preferred to crisp the membrane fraction to the point of becoming something like a breakfast cereal flake, ie., a Post® Toasties® or Kellogg's® Corn Flakes®. Indeed, it is strictly not preferred to turn the membrane to ash.
It is an object of the invention to improve utilization of a common by-product large-scale foodstuff or egg-laying operations, namely broken empty egg shells.
It is another object of the invention to separate a continuous input stream of broken empty egg shells into at least two output fractions, ie., a soft membrane fraction as well as, in contrast, a hard mineral fraction.
It is an additional object of the invention to separate a membrane fraction from empty broken egg shells without changing (much, if at all) the membrane fraction's delicate constituents (eg., molecules and the like), to the extent practicable.
It is an alternate object of the invention is to gain control over textural and structural changes to the membrane fraction as it undergoes the treatments pursuant to the method in accordance with the invention.
A number of additional features and objects will be apparent in connection with the following discussion of preferred embodiments and examples.